For many types of cancer, patient morbidity and ultimately mortility is due to the development of metastatic lesions. Experimental evidence suggests that tumors can inherently differ in their ability to form metastasis. As yet there is no available test to determine if particular human tumors are of high or low metastatic potential. Recent evidence suggests that the expression of the nm23 gene is related inversely to the metastatic ability of a number of tumor cells. We propose to transfer the nm23 protein coding sequence to a bacterial expression plasmid. The expressed nm23 protein will be isolated and used in the generation of polyclonal and monoclonal antibodies. In phase II, we will test whether these antibodies can be used to determine the level of nm23 protein in tumor samples, and whether this level is associated with metastatic propensity of a tumor. Potential application: A test to determine risk to a patient of relapse from metastatic lesions by measuring the level of nm23 in a tumor sample.